1. Field
This invention is in the field of internal combustion engines, particularly automotive engines having rocker arms and push rods and more particularly concerns that structural portion of a rocker arm which contacts the upper end of a push rod, and further concerns the push rod construction, per se and the combination of an internal combustion engine employing the present rocker arm and push rod.
2. Prior Art
Heretofore, the receiving socket for the upper end of a push rod of a typical internal combustion engine rocker arm has been a concave surface in which the rounded upper end of the push rod nests and which end can actually rotate about its longitudinal axis within the socket since the lower end of the push rod also nests in the concave top of a push rod (or valve) lifter. In these structures there is no actual mechanical linkage connection of either end of the push rod to any other part of the valve opening and closing mechanism. As a result, and as a consequence of the rapid, repeated impact force on the push rod receiving socket on the rocker arm, particularly at rpm's such as 9,000 or more, this socket is typically destroyed before its time as well as incurring premature breakage of the adjacent portions of the rocker arm.
Also inherent in prior rocker arm constructions, particularly wherein solid (non-hydraulic) lifters are employed is the loose contact of the push rod with the rocker arm especially in a cold engine. This looseness can cause the valves to open a lesser degree than optimum designed operating conditions require.